Demulsifying compositions



Patented Feb. 10, 1948 Emil A. Vitalis,,East Portchester, Conn., assignor to American Cyanamid Company. New York, N. Y., a corporation of Maine No Drawing. Application May 8, 1946; Serial No. 668,307

This invention relates to demulsifying compositions of a typesuitable for use in breaking either oil-in-water emulsions or water-in-oil emulsions of mineral, vegetable or synthetic oils, ,waxes, resins and the like, including those preparedby the use of soap or synthetic emulsifying The invention includes the novel deagents. mulsifying compositions hereinafter described and processes of breaking emulsions of the water-in-oil type or the oil-in-water type by subjecting 'the emulsion to the action of a de-' mulsifying agent containing thesecompositions. T 'In its broader aspects, the invention includes demulsifying compositions containing a surfaceactive ester of an'aliphatic sulfopolycarboxylic acid together with an aspartate amide-of an .-q

aliphatic sulfopolycarboxylic acid, as hereinafter defined. I have found that these two classes of demulsifying agents cooperate to produce results which are not obtainable with either ingredient whenused alone, and that a much more effective demulsifieris obtained when the two types -of compounds are used together. r I The surface-active esters of aliphatic sulfopolycarboxylic acids are well-known demulsifymg agents. "Thus, for example, in U. S. Patent No. 2,072,085 the efiectiveness of thesalts and estersof sulfosuccinic acid is demonstrated in the treatment of oil-field petroleum emulsions of thewater-in-oil type. Similarly, the effectivene'ss of the esters and salts of sulfotricarboxylic acids as demulsifying agents is stated specifically inU. S: Patent No. 2,315,375. Any of the aliphatic sulfopolycarboxylic acid esters described in either of these patents may be used in the compositions ofthe present invention, and therefore the preparation of specific compounds ofthis class need not be described in detail. I prefer to employ the diesters of aliphatic sulfodicarboxylic acids such as diamyLdihexyl, dioctyl or didecyl sulfosuccinates, since these have produced excellent results in practice However it should be understood that the esters of aliphatic sulfotricarboxylic acids, and particularly the 'triesters such'as tributyl, triamyl or trihexyl sulfotr-icar-' ballylate may also be employed if desired. It

9 Claims. (Cl. 252-336) 2 ing radicals, nis 1 or 2 and X is a cationic salt- .forming radical, these compounds being described in U. S. Patents Nos. 2,028,091 and 2,315,375.

The aspartate amides of aliphatic suifopolycarboxylic acids used inthe compositions of the present invention are compounds having the formula 00.01:). xso.-R

eo.N

V i CH:.C0.0 R: in which R is the residue of an aliphatic polycarboxylic acid, R1 is an alkyl or aikoxyalkyl radical of 8-18 carbon atoms, R2 and R3 are members of the group consisting of hydrogen, cationic salt-forming radicals and alkyl radicals. each X is a member of the group consisting of a hydrogen and salt-forming radicals and n is 1 or 2. These compounds are preferably prepared by reacting an N-alkyl or alkoxyalkyl substituted aspartate with maleic anhydride or with maleic or fumaric' acid, or with an alky maieate or fumarate or with aconitic acid or anhydride or a salt or ester thereof followed by sulfonating the resulting mono-amide. Suitable methods of preparation are described in the following specific examples. Although the compounds prepared from the esters of maleic or fumarie acid such'as the dimethyl, diethyl or dibutyl esters,

will be understood that the term surface-active esters of aliphatic sulfopolycarboxylic acids is intended to mean compounds of the formula carboxylic acid, B} is an allrylr radical of .4-18,

carbon atoms, 32- is amember of the 'g'roup cfonq may be employed if desired, I prefer those compounds in which the carboxylic acid groups of the aspartate radical are neutralized with a cationic salt-forming radical, and are therefore in the form of carboxylic acid salts. The sodium, potassium and ammonium salts are preferred. This is also true of the free carboxylic acid radical or radicals of the aliphatic sulfopolycarboxylic acid, corresponding to --C0.0X in the above formula. u

As is indicated above, the two essential ingredients of the compositions of my invention may be used in any desired ratio; 1; e., the quantity of aliphatic sulfopolycarboxylic acid esters may be greatly inexcess of the quantity of aliphatic sulfopolycarboxylic' acid aspartate or vice versa. However those compositions in which a surfaceactive ester of an aliphatic sulfopolycarboxylic acid is present in amounts at least equal to or preferably greater than the amount of aspartate sisting of alkyl radicals and cationic salt-form amide are preferred, since the aliphatic sulfopolycarboxylic acid esters are usually cheaper than'the aspartate amides. In general, I prefer those compositions containing about 5-9 parts by weight or the aliphatic 'sulfopolycarboxylic acid or even sometimes in greater quantities. for example, a wide variety of-oil-field petroleum emulsions of the water-in-oil type can be broken 3 ester for each 1-6 parts of an aspartate amide of an aliphatic sulfodicarboxylic acid of the type defined by the above formula.

In the demulsifying compositions of my invention the active demulsifying agents may be dissolved i water or in an organic solvent'such-as methyl, ethyl or propyl alcohol-or in a non-polar solvent such as benzene, toluene and the like. Concentrated solutions are preferably prepared in water-soluble solvents such as ethanol -or propanol and may be added to the emulsion as such or after dilution With water or other-:solvent to the desired concentration.

One of the principal advantages of the compositions of the present inventionresides in; the

range of concentrations in which they may d e,

used. Experience has shown that the aliphatic.

"good demulsifyingagents at one particular ratio of esterto emulsion but show a sharp reduction in their-demulsifying power when used in smaller Thus,

with sodium dioctyl sulfosuccinate when used at a concentration of 0.05%.:based on the Weight of the emulsion, but the resolutionds incomplete when smaller quantities are .used. .'In tests conducted with the same emulsion, which was an emulsion of salt, water in California crude oil, successful results were obtained throughout a range of 0.025-0.25% of a demulsifier Containing equal quantities-oisodiurn dioctyl sulfosuccinate and the, compound H NaOgS-GiCOONa elllHll' Et QN,

. CHiCOONa 11.00 ONa The compositions of thepresent invention give a much faster and more Y complete resolution of emulsions than do the corresponding esters of aliphatic suliopolycarboxylic acids when used alone, and this action persists throughout a much Wider range oi concentrations of .dem'ulsi'fying agent in the emulsion.

fAlthough excellent results are obtained with compositions in which the two types of ingredients specified above constitute the only demulsifyingag'ents'pi'esent, it will'be understood that the invention includes compositions in' which also present. Thus, for example, salts of aromatic sulfonic acids or their condensation prodnets with formaldehyde or other aldehydes, a1- kylated aryl sulfonates such as sodium isopropyl naphthalene sulfonate, sodium'kerylbenzene sulfonate, ethylene oxide condensation products of alkylol amides of higher fatty acids' such as ethanol stearamide and the like maybe present in the compositions .of the present invention if desired. These and other known demulsifying agents can frequently be used to advantage by thoseskilled in the artas ingredientsof the compositions of the presentinvention.

pumped, or it may be added to storage tanks containing the emulsion, or it may be brought into contact with or caused to act upon the emulsion in any of the various types of apparatus now generally employed to resolve or break emulsions, and at-ordinary or [at elevated temperatures. In the treatment of oil-field emulsions the compositions may be used with success at 7 ratios of active demulsifying agent to emulsion oi -1,: 1;0,(l00-or higher, although for best results I the range of .0250.25% given above is usually preferred- Inbrealcing emulsions of the oil-in- -water type-it iisgfrequently desirable to use larger quantities' oi the demulsifying agent.

Althoughthe-iollowing examples may describe certain preferred embodiments of the invention,

they. are given primarily for purposes of illustration."'fhese examplesdescribe particularly the method of preparation-oi the aspartate amides of a-liphatic-sulfopolycarboxylic acids, sincethese methods arenot readily available. As is noted above, the methodsof-preparing the aliphatic sul fopo'lycarboxylie -acid--esters are quite wellknown, and are describedin the patents referred to at;rthe beginning-pi the-present specification.

. heated tor 10 minutes. After evaporating. the

solyent theN-dodecyl .N-tdisodium.sulfosuccinyl).

dimethyl aspartate was obtained -as a cream colored solid. -Thi produc -ma eeused as suc to d ture withaesters ofaliphatic sulfopolycarboxylic acidsgorgit nay beconverted into the N-dodecyl liedisodi m u q u n l) d s d m sp t by saronifl ation with e cess. od m y roxiqq so ution.

,Ami'xture of do grams of triamyl sulfotrlcar ballrla and 2.0 exams of the N-dodecyl -N-(d1- sodium 111iosuccinyl) dimethyl aspartate was dissolved ,m '50 :cc. oliisopr-opanol. This solution was added to an emu s n o e watereineol-l tsbweihoi other known or approved demulsifying agents are type byfiglta'lng 25 y t seaswater with,-7.5 parts of a California crude petroleumfromthe Ventura Avenue field. The emulsion was, broken at 8. c cen atio f 0 1. of .the. ,demulsifying.composition (100% solids)v based-on the weight of the emulsion.

' Emm l Z 14% grams .of,;dimethyl .maleate was added slowly .with stirring t0v a sfllutionnf ,265, grams In practicing the process of the present invention, in which emulsions of the oil-in-water type prof the water-in-oil type are broken or resolved by contact with the compositions defined above, any of the known methods of treatment may be used. The demulsifying composition may beadded continuouslyor intermittently to pipe lines through which the emulsion is being of octadecylamine .i'nWSOQ cc. oitertiarybutanol a 5 Qan -t emixture was all d to standat 23 c. ionfidhohfs/ 5100 gra s of'maleic anhY: dridewas then added-slowly with agitation at 5060 C. and the mixture was heated at -90 C. for one hour "to insure completion of the reaction. The product was then sulfonated by slowly adding the-:maleamic acid solution to a soluti n o grams of. sodiu lfi e H1300. 9-

, of hot flwater with-good agitation. The :sulfonation produptfN octadecy1 N-(disodium sul'fosuc cin'yl) -'dimethy1 aspartatei-was-obtained-as a clear evaporated to dryness.

yellow solution which dried to a cream-colored powder, v Equal parts by weight'o'f this powder and of sodium dioctyl sulfosuccinate were dissolved 'in isopropanol and used for the resolution of a petroleum emulsion of the water-in-oil type, prepared as described in Example 1. The emulsion was broken at concentrations of 0.05% of the mixture, based on the weight of the emulsion.

' A sodium salt was prepared by adding a concentrated aqueous solution containing 8 grams of NaOH to 40 grams of the N-octadecyl N-(disodium sulfosuccinyl) dimethyl aspartate and allowing the mixture to stand for 2 hours. The solution was then adjusted to a pH of 7 by adding dilute hydrochloric acid and the product, N- octadecyl N-(disodium sulfosuccinyl) disodium aspartate, was recovered by evaporating the solution. The product was mixed with sodium dioctyl sulfosuccinate to form a solutioncontaining 40 parts by weight of each of the two surface-active agents (100% basis) and 20% isopropanol. This mixture broke the same emulsion at a concentration of 0.025%.

1 Example '3 N-amoxypropyl dimethyl aspartate was prepared by dissolving 145 grams of amoxypropyle amine in 400 cc..of tertiary butanol, adding 144 grams of dimethyl maleate slowly and allowing the mixture to stand for 75 hours, followed by in 150 cc. of water and the mixture was heated at 80-90 C. for one hour. The resulting solution was evaporated to dryness yielding N- amoxypropyl N-(disodium sulfosuccinyl) methyl aspartate of the formula NaO3SCH.CO.ONa

oamoclnu A mixture of 9 parts by weight of sodium diamylsulfosuccinate with one part of this product was dissolved in 10 parts of isopropanol. When tested on the emulsion described in Ex: ample 1 it was found to be an efi'ective demulsifier at a concentration of 0.04%.

Example '4 sodium N-octadeeyl N (1,2 dicarbomethoxyeth'yll) sulfotricarballylamate, a soft orangecolored water-soluble solid.

"This product was tested as a demulsifier in admixture with -60% of its weight of sodium di- The product was tri octyl sul fosuccinate and of trihexyl sulfotricar} ballylate, and the mixtures were efiective when tested against the emulsion described in Example 1 at concentrations of 0.02-0.04%. Even better results were obtained from a portion which was saponified with an excess of strong sodium hydroxide solution to produce the pentasodium salt of the formula CHzCOONa Naol o-omcoom omcoom I mooom 4 A solution of 6 grams or this product and4 grams of sodium dioctyl sulfosuccinate in 10 cc. of ethanol was tested on the same water-in-oil petroleum emulsion and was found to be an excellent demulsifying agent at 0.025% concentration. Q 7 i Example 5 The demulsifying compositions described in the preceding examples are of great value in separating industrial emulsions, many of which are very troublesome. Thus, for example, in the extraction of vanillin from neutralized sulfite liquor with benzene an emulsion of the oil-inwater type containing about equal volumes of benzene and sulfite liquor is formed which is stabilized by the colloids of the sulfite liquor and is very dimcult to break. I have found, however, that this e'inulsion can be separated by treatment with compositions of the present invention. u

A sample of the emulsion treated with amounts up to 0.25% its weight'of sodium dioctyl sulfosucef cinate was broken only very slowly and with difiiculty. Addition of a water solution of N- octadecyl N-(disodium sulfosuccinyl) disodium asparate; prepared as described in Example 2, gave similar results. However, upon adding is." water solutioncontaining 12.5% of sodium di octyl sulfo'succinate and 12.5% of N-octalecyl N- (disodium sulfosuccinyl) disodium aspartate in amounts of 0.4% on the weight of the emulsion (corresponding to 0.1% of the active materials) the emulsion broke in 2 minutes.

What I claim is:

1. A demulsifying composition comprising a mixture of about 17% to by weight of a surface-active ester of an aliphatic sulfopolycarboxylic acid and about 83% to 10% by weight of anaspartate amide of'an aliphatic sulfopolycarbon atoms, R2 and Rs are members of the group consisting of hydrogen, cationic salt-forming radicals and alkyl radicals, n is a whole number not greater than 2 and each X is a member of the group consisting of hydrogen and cationic salt-forming radicals.

2. A demulsifying composition comprising a mixture of about 17 '%-to 90% by weight of a surface-active ester of an aliphatic sulfopolycarboxylic acid and about 83% to 10% by weight bon atoms, R: and R3" are members of the group surface-active ester of an aliphatic sulioiiolycarboxylic acid and aboutosa, to by weight of an aspartate sulfosuccinamate having the formula XS0PQ+C0.OX

I )R'i Ef K 2 \omeooa, HziGOfO R: injwhich'Rr is a"me eer of'the group consisting of alkyl and aikoxyalliyl radicals or "8-18 carbon atom,;R2"and R3 are members of thefg'roiipconsistingbfliydrogen, eationicvsalt forining radicals and aikyl radicals and each xis a memberiof the group consisting of hydrogen "andifcationic saltforming radicals. g

4. A 'deinulsifying 'composition--. 'coinpri's'inga mixture'of 5-9 parts by weight-ofa surface-active ester'ofan aliphatic sulfopolycarboxylic acid and 1 6 parts of an aspai'tate amide ora aliphatic sulfopolycarboxylic acid of. the formula "(00.055)" XO:SIR

coin.

carboxylic acid, R1 is a member of the .groupconsistingyof alkyl and alkox'yalkyl radicalsho'f 8A8 carbon atoms; R; and R3 are members oi the group consisting of hydrogen, cationic salt forming radicals and alkyl radicals, n is a whole numher not greater than 2, and each- X is a member of the group consisting of hydrogen and cationic salt-forming radicals.

5. A demulsifying composition comprising a mixture of 5-9 partsrby weight of a surface-active consisting of hydrogen, cationic sall' formingradicals and alkyl radicals and. eacl iflMflis-an elkali metal.

6; A difiuisifying "compositionwomprising a mixture of 5-9 parts by weight of sodium uitetyi suliosucc'inate and 1 -6 parts by weight 'oi 'N- oct'adecyl N-"(disociii'im sulfo'su'ccinyl) disodiiim as'paitat. I 7. A"process fo'rpreaking aqueous emulsions whicliboniprise's subjecting the emulsion tothe action. of a 'demulsifying agent comprising asth rincipal active demul'siiy'in'g ingredients a mixture or master iii an aliphatic 'sulfopolycarbox ylic acid and .acompound 'o'f'the formula in which R is the residue of an aliphatic polyca'r boxylic acid, R1 is a'member of the group consisting of alkyl and alkoxy'alkyl radicals of -8'-18 carbonatoms; R2 and R3 are members of the group consisting of hydrogen, cationic salt-forming radicals and alkyl radicals; n is a whole number not greater than 2 and each X is a member of the group consisting of hydrogen and cationic salt -forming radicals, the two ingredients being present in a weight ratio of about '1'1%'to 90% of the firstte about 83% to 10% of the second.

8. A process'for breaking aqueous emulsions which comprises subjecting the emulsion to the action'of a demiilsifying agent comprising the principalactiie *demulsifying ingredients a mixture an ester "of an aliphatic sulfopolycarbox-' ylic acid and a compound of the formula in which X is a member of the group consisting of hydrogen and cationic salt-forming radicals, Y is a member of the group consisting of hydrogen and CH'zC'OOX,'R1 is a member of the group consisting of alkyl and alkoxyalkyl radicals and R2 and R3 are members of the group consisting a 00' in which R is the. residue of an aliphatic poiy- REFERENCES CITED V Theiollowing references are 0f record in-tha file of this patent:

UNITED STATES PATENTS Number Name Date 2,072,085 DeGroote et a1; -.-Ma'r'. 2, 193? 2217,38? Shapiro e. -e Oct. 8,-. 1940' 2,236,528 Epstein et al. .....-a- Apr. 1, 19% 2,305,067 De Groote --s Dec. 15,1942 2,315,375 Nawiasky et a1 s. Mar. 30,4943 2,268,067 Lynch-2 ee Jan,23-, 1945 2,379,535 Lynch et al. July 3, 1945 

